The present invention relates to a support and transport roll or roller for metal ingots particularly for use in continuous casting e.g. of steel, such as a roller is assumed to have a core with cooling channels in its surface and being inserted in a tubular sleeve whose inside is correspondingly grooved for closing these channels. In addition the invention relates to the making of such a core and of associated structure.
German printed patent application 1583619 discloses a transport and support roll or roller for use in the transport path of continuous casting machines and having a hollow axle or shaft to serve as conduit for a coolant, also providing appropriate journal mounts acting between shaft core and outer sleeve. The particular configuration as disclosed is disadvantaged by the fact that the sleeve is a very complicated object to make. This is particularly so since its wall thickness is significant. Another drawback of this arrangement is the fact that charge and discharge of coolants through conduit channels is carried out through turning bearings arranged on the side inside of the roller. Such a construction requires a rather cumbersome, expensive and complicated conduction arrangement for the coolant to the front ends of the roll and the back.
U.S. Pat. No. 2,998,999 discloses hydrostatic bearings which are arranged on a shaft outside of the outer sleeve and require their own liquid supply. This too is a rather complex kind of arrangement. U.S. Pat. No. 4,631,792 corresponding to German patent 32 31 433 discloses an internally cooled support and/or transport roller with an outer sleeve which is connected to the core by welding in between the channels through covering all of the surfaces of contact as between the sleeve and the core. In order to provide for the welding a groove is worked in the sleeve and is then filled with welding material. This kind of arrangement is disadvantaged by a high tension load in the groove. Also, the welding electrodes require very complex guiding because the sleeve groove provides inherently a rather narrow area of working.
The same German patent discloses also the providing of a connection between sleeve and core such that in the front face of the bar (that separates cooling ducts) a thread is cut which engages a corresponding thread of the inside of the sleeve. In still another version the rod or bar between cores and the cooling channel is configured in a trapezoidal threadlike fashion. The bar has its front face connected or cooperating with the corresponding engagement in the inner jacket of the sleeve. Both kinds of configurations are disadvantaged by the fact that the sleeve is connected to the core only in a form and shape closed manner which makes it possible that there is movement between the elements.